What is an incompetent cervix?
An incompetent cervix is also called cervical insufficiency. The cervix is the bottom part of your uterus (womb). Normally, the cervix remains closed during pregnancy until your baby is ready to be born. A normal pregnancy lasts for about nine months. An incompetent cervix may begin to open at 4 to 6 months of pregnancy. At this time, the cervix may begin to thin and widen without any pain or contractions. The amniotic sac, also called the bag of water, bulges down into the opening of the cervix until it breaks. This may cause a miscarriage or premature (early) delivery of your baby.